Letter Pair Counting and Alphabet Patterns: Pairs of Letters in a Word, Forward and Backward Order Questions for SSC

A classic question in SSC reasoning is: “How many pairs of letters in the word STUDENT have as many letters between them (in the word) as there are between them in the English alphabet?”. This guide on letter pair counting for SSC gives a reliable method, with solved examples for the forward, backward and both-direction versions, practice questions and FAQs.

The Question

You are given a word. A pair of letters is counted if the number of letters between them in the word is the same as the number of letters between them in the alphabet. Variations:

Alphabet Position Table

Method

1. Write the position of each letter of the word (as per the alphabet) below it.
2. For every pair of letters at the positions i and j in the word (i before j), find the distance in the word, j − i.
3. Find the difference of their alphabet positions.
4. Forward: count the pair if the alphabet difference (later letter minus earlier letter) = j − i.
5. Backward: count if the alphabet difference = −(j − i), i.e. the earlier letter has the higher position.
6. Count each pair once.

Tip: Pairs of adjacent letters in the word with consecutive letters in the alphabet (like S–T) are the quickest to spot; for these the number of letters between them is zero in both the word and the alphabet.

Solved Examples

Example 1: STUDENT (Forward)

Letters with positions: S(19) T(20) U(21) D(4) E(5) N(14) T(20).

Check pairs where the alphabet difference equals the word distance:

No other pair satisfies the condition. The answer is 4 pairs (ST, SU, TU and DE).

Example 2: STUDENT (Backward)

The pair S (1st) and N (6th): word distance 5; alphabet difference 14 − 19 = −5, which is the reverse order. So the answer is 1 pair (SN).

Example 3: DEFIANT (Forward)

D(4) E(5) F(6) I(9) A(1) N(14) T(20): D–E (1, 1), E–F (1, 1) and D–F (2, 2). The answer is 3 pairs (DE, DF, EF).

Example 4: PROMISED (Backward)

P(16) R(18) O(15) M(13) I(9) S(19) E(5) D(4): P (1st) and M (4th): word distance 3, alphabet difference 13 − 16 = −3, so the pair counts in the backward order; E (7th) and D (8th): 4 − 5 = −1, word distance 1. So the answer is 2 pairs (PM and ED).

Example 5: FRIDAY

F(6) R(18) I(9) D(4) A(1) Y(25): no pair satisfies the condition. The answer is 0.

Other Alphabet Pattern Questions

Tricks

• Write the positions of the letters and compare, and do not try by sight for the long words.
• Look first for the consecutive letters (like S–T–U, D–E–F) in the word.
• For the backward pairs, look for the reverse consecutive pairs (like E–D, or P . . M).
• Repeated letters (like T in STUDENT) count as different positions and can form pairs.

Quick Tips

• Write the alphabet positions below the letters.
• Spot the consecutive letter pairs first.
• Check the direction (forward or backward) as per the question.
• Count each pair once.

Quick Revision Points

• A pair counts when the word distance equals the alphabet distance.
• Forward: the later letter has a higher position.
• Backward: the earlier letter has a higher position.
• Adjacent consecutive letters always form a pair.
• The opposite letter of a letter at position n is 27 − n.

Practice Questions With Answers

1. How many pairs in the word STUDENT (forward)?
   Answer: 4
2. How many pairs in the word STUDENT (backward)?
   Answer: 1
3. How many pairs in the word DEFIANT (forward)?
   Answer: 3
4. How many pairs in the word PROMISED (backward)?
   Answer: 2
5. How many pairs in the word FRIDAY (in any direction)?
   Answer: 0
6. How many pairs in the word BREAKFAST (forward)?
   Answer: 1 (ST)
7. How many pairs in the word CLOUDINESS (forward)?
   Answer: 1 (LS)
8. What is the opposite letter of D?
   Answer: W
9. How many letters are between D and K in the alphabet?
   Answer: 6
10. In the word ABOVE, how many letters are in the same position after the alphabetical arrangement?
    Answer: 2 (A and B)

How to Practise This Chapter

Practise 10 questions every day and write the steps on paper. Then attempt timed sets from our practice papers and the previous year papers page. See all topics on the Verbal Reasoning notes page, read the previous topic Substitution Coding and the next topic Letter Analogy and Alphabetical Analogies.

Frequently Asked Questions

What is a letter pair counting question?

A question that asks the number of pairs of letters in a word with the same gap as in the alphabet.

What is the forward order?

The same order as in the alphabet (A before B).

What is the backward order?

The reverse order of the alphabet.

How do I count the letters between two letters in the alphabet?

Subtract the positions and subtract 1.

Do the repeated letters count?

Yes, as they are at different positions.

What is the quickest way to find the pairs?

Look for the consecutive alphabet letters near each other.

Is this topic asked in SSC?

Yes. It is asked in SSC CGL, CHSL and MTS reasoning.

How much time should I take?

About 40 seconds.

What is the opposite letter of E?

V.

What is the position of the letter M?

13.

Do I count the pairs twice for the both-direction version?

No. Count each pair once, whichever order it is in.

How can I practise?

Take any word and check all the pairs with the positions.